using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

/****************************************************
// 功能：渐变工具类
// | Talk To [ 聊来改善地区金融服务环境，助力企业发展 ]
// | Copyright (c) 2021-2025 聊来 All rights reserved.
// | Licensed ( <a href="http://www.apache.org/licenses/LICENSE-2.0">聊来</a> )
// | @Author: 贯彻己道的云 <18970881148@qq.com>
// | DateTime: 2024/12/30 16:44:56
*****************************************************/


[AddComponentMenu("UI/Effects/Gradient")]
public class Gradient : BaseMeshEffect
{
    [SerializeField]
    private Color32 topColor = Color.white;
    [SerializeField]
    private Color32 bottomColor = Color.black;
    public override void ModifyMesh(VertexHelper vh)
    {
        if (!IsActive())
        {
            return;
        }
        int count = vh.currentVertCount;
        if (count == 0) return;
        List<UIVertex> vertexs = new List<UIVertex>();
        for (int i = 0; i < count; i++)
        {
            UIVertex vertex = new UIVertex();
            vh.PopulateUIVertex(ref vertex, i);
            vertexs.Add(vertex);
        }
        float topY = vertexs[0].position.y;
        float bottomY = vertexs[0].position.y;
        for (int i = 1; i < count; i++)
        {
            float y = vertexs[i].position.y;
            if (y > topY)
            {
                topY = y;
            }
            else if (y < bottomY)
            {
                bottomY = y;
            }
        }
        float height = topY - bottomY;
        for (int i = 0; i < count; i++)
        {
            UIVertex vertex = vertexs[i];
            Color32 color = Color32.Lerp(bottomColor, topColor, (vertex.position.y - bottomY) / height);
            vertex.color = color;
            vh.SetUIVertex(vertex, i);
        }
    }
}
